Gaucher disease (GD) is caused by deficiecy of activity of the enzyme glucocerebrosidase and consequent storage of the substrate glucocerebroside in cells of macrophage/monocyte lineage. Based on the presence and rate of progression of neurological symptoms, GD is classified into non-neuronopathic and neuronopathic forms. We investigated the methods to differenciate these two subtypes by mutation screening and to establish the treatment for neuronopathic GD.We studied mutation prevalence mong 47 unrelated Japanese patients with combination of PCR and SSCP.Eighty percent of total mutated alleles could be identified with this methods, however, it is impossible to distinguish non-neuronopathis from neuronopathic GD.Also we produced recombinant adenovirus that express human glucuronidase and this recombinant adenovirus to animal model intravenously. Pathological abnormalities in liver and spleen were improved, and the urinary glycosaminoglycans were also reduced in treated mice. Transduction of enzyme into brain was seen only by adminstration of direct injection of recombinant adenovirus into the lateral ventricles.